Try to fix flakiness of StressTest#testInsertOfManyRowsUsingManyThreads

Using JUnit4 which may allow a longer timeout instead deprecated JUnit3

Bug: 168307913
Test: atest --iterations 100 CtsLibcoreTestCases:tests.java.sql.StressTest#testInsertOfManyRowsUsingManyThreads
Change-Id: I3e6c3cf362815830f6955738e9443c6b497012cc
1 file changed